Wintertires

As I want to drive the speedster the whole year, I want to change to
wintertires. This is not really an option on the standard wheels. Ofcourse
I could get the factory Opel wheels, but they will probably very expensive.
Arno just got new wheels for his summer tires from
Compomotive. They seem seem to
be nice, have a good finish, are strong and not very expensive.

So I first had to choose the sizes I was going to use. I would like to end up
with the Elise settings eventually, so 15" front and 16" rear.
But I don't want to change the height of the complete wheels just yet,
because I don't have height adjustable suspension. So after some calculating
I came up with the following sizes for the wheels:

Front:

15"

6,0J

ET26

Rear:

16"

7,0J

ET36

I want to go for the MO model which is available in most sizes. Unfortunatly
ET26 is not possible in the MO series, so I had to go to ET25. Close enough
though.

Final order looked like this:

2 x MO 6,0x15 ET25

2 x MO 7,0x16 ET36

PCD: 5x110

Center borde: 65.1mm

Color: black

There are not many distributors in the Netherlands for Compomotive. Arno found
a good one, which actually wants to put some effort in finding stuff out and
chasing the distributor. It is Dutch Power Trading.

After I ordered the wheels, there seemed to be some confusion at Compomotive.
They were afraid the wheels would interfere with the brakecalipers. So they
sent me a sheet to do some calculations.
After a week I got a response back saying the rears would be ok, but the front
had to be ET20. I didn't agree and ordered ET25 anyway. If it wouldn't fit I'd
rather put a spacer in there in stead of having to modify the wheels.

After four weeks the wheels had been made and I could pick them up.

Unpacking the boxes

I brought the speedster along to see if it was nessacery to get longer bolts.
Fortunatly this wasn't required. However, there was a powdercoating on the
inside of the wheel, which made it impossible to fit the wheels on the hub's.
Fortunatly some sanding the coating away did the trick. Arno didn't have this
problem with the wheels for the Elise. It seems they made the center bore 0.1mm bigger and they didn't with mine.

Sanding the powdercoating of

Putting back the bolts

Fitted wheel

So the wheel fitted, but 15" is as small as you can go. And the ET25 also
doesn't leave much space to spare, but it works. If you want to do the same it
might be better to go to a ET24 or smaller, but I think I'll leave it at this
unless I run into problems.

15" is as small as you can go with the standard brakes

Not a lot of space left

Fortunatly the rear wheels were a lot easier. They just fitted out of the box.
Lots of space left, but I allready knew that.

No problems at the rear

So after some sanding of the other wheels everyting was ok. Looks a lot better
in black :)

Jacked up, fit the wheels

Black looks better IMHO

After we packed the wheels up, we drove by Roline to see if we could drop of
the wheels so they could fit the tires and make an appointment for them to be
fitted. Fortunatly they were still there (we were a bit late), and I could
come by the next morning.

The tires I ordered are the Dunlop SP Winter Sport M3. I originally wanted
to go for the Toyo's, but they can't do the front and the rear tire from the
same series. Sizes I ordered were:

front: 185/65R15 88T

rear: 205/55R16 91T

They come pretty close to the original tires (both are 0.4% smaller).

New tires

Pretty happy with Roline fitting the tires. They really take the time to fit
them right. On balancing the wheels they found that some of them would have to
be adjusted with too much weight for their liking. So they took the tire of
the wheel, and rotated it a bit to reduce the weight difference.

Putting the tire on the wheel

To much weight needed, so they refit the tire on the wheel

and ofcourse got it balanced to a perfect 0.

finished wheel

To make sure the front wheels would come off without to much of a problem, Arno
put some Mobyleen grease on the inside, to stop them sticking.

Some grease for the front wheels

Car looked pretty good with the new wheels and tires. Think the black nicely
hides the bigger wheels and looks ok with the yellow.

With the original wheels and tires

With the winter wheels and tires

Running the tires now on 1.6bar front and 1.7bar rear. Seems to work ok. Grip
is pretty good. The grip limits are much more clear and the car is more stable
during cornering, acceleration and braking. There is more flexibility in the
tires though, so reactions are a bit more vague. This has to do with the high
thread on the tires and the flexible side walls. Requires some getting used to
but isn't annoying.